Food Preservation: Getting to the Root of It
By Jennie Shurtleff
Since ancient times, people have devised a number of ways to preserve the food that they raised, foraged and hunted. Fruits, like apples, were often dried. Meat was often salted or placed in a brine, and root vegetables were often stored underground.
Some of the first people known to have preserved food by burying it were the indigenous people of Australia. The practice didn’t catch on in Europe until much later, in the 17th century, when the first walk-in food storage cellars – or what we commonly think of as a root cellar – appeared. Although used in England, root cellars became far more commonplace in the New World, especially during the 17th and 18th centuries. During this time period, almost every farmstead in what is now New England had a root cellar that enabled people to keep their produce cool in the summer, but above freezing in the winter.
The design and style of these early American root cellars varies dramatically. While some root cellars were part of the main cellar beneath a home, others were elaborate separate structures that were built into the side of a hill and lined with either brick, stone, or logs. These subterranean vaults varied in size from 3-4 foot square holes to large chambers that were over 20 feet in length and tall enough so that a person could walk into them and stand upright. In addition to these formal structures, many people made root storage areas by simply digging trenches in a convenient area where their vegetables could be buried and then later recovered as needed.
While root cellars vary in appearance, there are some critical elements that effective root cellars share. First, the temperature in a root cellar needs to be consistently somewhere between 32 and 40 degrees F. In this temperature range, the growth of microorganisms that leads to the decomposition of food is slowed. Second, root cellars need to maintain an 85-90 percent humidity level. The need for damp air is one reason that root cellars often have dirt floors. Soil naturally holds moisture and can easily be wetted down if additional humidity is needed in the chamber. Third, root cellars must have good ventilation. Areas that lack proper ventilation are more prone to mold which can lead to decay of produce. Having adequate ventilation also allows for air circulation and draws off the ethylene gas that is produced by some vegetables and fruit and can cause other produce to spoil. Fourth, root cellars should be dark. Most produce lose their nutritional value and begin to break down if exposed to direct sunlight. Moreover, sunlight can cause many root vegetables to sprout – which, in turn, renders them unpalatable.
To insure that a root cellar is cool, humid, well-ventilated, and dark, many root cellars are ten feet below the ground with a ventilation chamber or chimney. While the name root cellar suggests that root vegetables, such as potatoes, beets, onions, turnips, and carrots, were stored in the cellar, historically other types of food, such as winter squash, cabbage, and pumpkins, were placed there as well. In fact, some cellars had special chambers within them for storing fruit, such as apples, as well as meat and produce like butter, milk, cream, and cheese. If properly stored, root crops such as potatoes can last as long as 5-8 months. Cheese can be stored for up to six months, while other dairy products like milk and cream can be stored for several weeks.
While we may think of root cellars as something from the distant past, they actually made a come-back during the Great Depression and World War II. The Farm Security Office and the Office of War Information encouraged the use of root cellars as a means of preserving food so that it wouldn’t be wasted and would help prevent food shortages.
Image that was originally released by the Office of War Information in 1942 in order to teach and encourage people to preserve food that otherwise might spoil.
From the collection of The Library of Congress.
As with so many things from history, what is old is new again. There has been a resurgence of interest in root cellars over the past few decades. For anyone who wishes to preserve produce the old-fashioned way, here are some tips:
Only store fruits and vegetables that are mature, unbruised, and don’t show any indications of insect damage or decomposition.
Don’t wash vegetables before you store them.
Keep containers that are used for fruit and vegetable storage off the floor so that air can circulate beneath them.
Harvest the produce that you plan to store when it is cool and the soil is dry.
Place root vegetables in damp (not wet) sawdust or sand.
Do not place vegetables in large heaps (keep your piles small to aid in air circulation)